How did oil jump from $20 to $138 a barrel in seven years?

The most common explanations are increased demand and lower supply, right?

It's becoming more clear that the real reason is unregulated trading of crude oil futures on the London and New York stock exchanges.

There was even a Senate report about this last year (did you blink and miss it?) which concluded that there's no oversight of the U.S. Commodity Futures Trading Commission. The folks who work there simply stopped enforcing the laws governing the U.S. Commodity Exchange Act, which says, “Excessive speculation in any commodity under contracts of sale of such commodity for future delivery . . . causing sudden or unreasonable fluctuations or unwarranted changes in the price of such commodity, is an undue and unnecessary burden on interstate commerce in such commodity,” and it directs the government to regulate the trading of these commodities to control unnecessary burdens.